This invention relates to molded plastic products and more particularly to an apparatus for manufacturing such products including means for locating a structural load support insert member in a mold wherein the locating means includes means to separate the load support insert member from a mold part.
In the past it has been recognized that it is desirable to locate a load support or insert member in a mold to form a composite plastic product by a foaming process in which polyurethane material is foamed with respect to the insert.
One such method is set forth in U.S. Pat. No. 4,228,115 issued Oct. 14, 1980 to Gardner for Method of Making a Horn Pad. In this method a horn switch assembly is covered by a plastic film and then the assembly is foamed to form a plastic product with a load support insert, a covering film and a layer of urethane foam. While suitable for its intended purpose, the method of the '115 patent requires that the inserts be fabricated as separate components used in a second manufacturing step which covers the insert with the film and then moves the "covered insert" to the mold to carry out a foam operation.
U.S. Pat. Nos. 4,420,447 and 4,477,504 both disclose instrument panel constructions and methods for foaming material with respect to a load support insert. In both cases, however, the insert is supported on a mold cavity part and then the part is lifted from the mold cavity in a second manufacturing step.
U.S. Pat. No. 449,945 discloses use of transverse holding strips and manually releasable bolts to hold an insert in place. The holding strips, however, became part of the product. U.S. Pat. No. 1,592,671 discloses a mold reinforcing having tapered spacing lugs. The lugs, however, are not extended beyond the mold to be engaged by combination locating and part release mechanism. U.S. Pat. No. 3,871,060 disclose a method for manufacturing plastic mold parts in which the mold parts have projections defining passages for flow of injection molding material. The use of high strength preforms or inserts is not disclosed. U.S. Pat. No. 4,519,567 discloses the use of mold pins to support a reinforcing ring. None of these references disclose an insert with boss formations configured for engagement with a combination locating and release mechanism.